DALI MEGALINE AMPS & CROSSOVER

I agree lynott, one would expect going from digital amp(bass/mid- cone driver) to class- A amp(treble- ribbon) ones asking for trouble.  I’m sure any of the amp brands you mentioned above would sound great. Especially the Boulder & Classe Omega with their endless power reserves.

I can’t wait to hear some Deep Purple on these bad boys once properly setup! They were my first rock band back in ’72 at 10 years old! Highway Star!

Please send me info on the mods cerrot. I’m curious how much better/different the DBX 360 is?! I may even call Mr. Sanders since his speakers include an electronic crossover. Nice setup  

Thanks for chiming in Mr. Porter, I enjoy reading you thread very much! I have some many questions I want to ask you about the ML’s I don’t know where to start. But let me reply to a few comments you made. I know matching amps has to be better, but what’s amazing right now I have two different type/brand amps, two different length(4’ & 8’)/brand( MA-ANAP & AQ) speaker cables with cheap banana connectors, two different(one cheap, one good) interconnect brands, & last but not least the Beringer crossover & the system sounds AMAZING! The ease/clarity of the dipolar ribbon sound from the ground to the ceiling, the unlimited dynamic range sledgehammer bass, only one crossover electronic point adds up to the best speaker I have ever heard or owned. I can’t wait to get it all setup correct. How you ever went back to a point source speaker after the ML’s Mr. Porter I’ll never know.

Can you please explain to me why the 6” woofers are ‘more in need of what tubes do’? Never heard that before although I don’t doubt you for a moment!

Also, you mention the caps in the base are ‘to make the crossover operate properly’. I though the caps are to protect the ribbon from DC current back to it?

Regarding the lower crossover point with a stepper slope, if I’m not mistaken, my Apogee Stages crossed over at 800HZ at 6/12DB & My Apogee Studio Grands crossed over at 600HZ same slope with much smaller ribbons. Why can’t the Dali ribbon which is 91” tall do 800 say at 24DB?!

I will look into replacement ribbon for peace of mind because I don’t ever see me selling these speakers since that can’t be topped. Period.

Do you have any comments of me adding 3lbs of stuffing to each cabinet?

BTW- I did have them crossed over at 60HZ at 24DB with my subs, but didn’t like the bass. So now I’m running them full range & blended the subs in up to 50HZ. WOW is all I can say. I will be up again tonight until 3AM like every night for the past two weeks since I have had the speakers with my jaw ajar in disbelief!

 Check this out about the Beringer I’ve been disrespecting:

http://www.audioheritage.org/vbulletin/showthread.php?17457-Behringer-DCX2496-digital-x-over-any-good

http://freerider.dyndns.org/anlage/evaluierung.htm

Ptheo - here is a link to the modded Behringer.
http://www.behringermods.com/dcx2496.html

It is a sweet unit.  I upgraded to Rogers modded DBX as it has room correction (only used for 500 hz and below) and totally BLEW ME AWAY.  

How you ever went back to a point source speaker after the ML’s Mr. Porter I’ll never know.

Can you please explain to me why the 6” woofers are ‘more in need of

what tubes do’? Never heard that before although I don’t doubt you for a moment!

Also, you mention the caps in the base are ‘to make the crossover operate properly’. I though the caps are to protect the ribbon from DC current back to it?

Regarding the lower crossover point with a stepper slope, if I’m not mistaken, my Apogee Stages crossed over at 800HZ at 6/12DB & My Apogee Studio Grands crossed over at 600HZ same slope with much smaller ribbons. Why can’t the Dali ribbon which is 91” tall do 800 say at 24DB?!

I will look into replacement ribbon for peace of mind because I don’t ever see me selling these speakers since that can’t be topped. Period.

Do you have any comments of me adding 3lbs of stuffing to each cabinet?

BTW- I did have them crossed over at 60HZ at 24DB with my subs, but didn’t like the bass. So now I’m running them full range & blended the subs in up to 50HZ. WOW is all I can say.

I understand your comment about the difference between line array and point source. That is exactly what I miss about moving from Dali Megaline to Focal.

That said, the Focal is a better speaker, and should be considering the difference in cost. There is no perfect speaker, all are a compromise and overall there are at least half a dozen speaker designs that quality for best of best and dozens more that are almost in that category.

My comment about the 6” woofers refer to punch, power and foundation that makes music satisfying. It’s impossible to get 6” woofers to punch like the Focal 16” field coil but big powerful tube amps help close that gap.

If you use solid state on the Dali woofers you are likely hungry for more slam and weight and crossing the sub higher provides some of that.

If you look at Dali chassis and rear port design the free air resonance is about 35 HZ. It’s very difficult to get the speaker (any speaker) to continue output below that natural physical restriction.

Dali does an EQ that partially corrects that but it’s not possible to get it linear to 16 HZ like the Focal nor should anyone try.

Your comments about crossover points probably relate to this as well. When I ran my Megaline I had them operating full range and then brought in twin JL Audio F212 subs at 24 DB per octave at 30 ~ 35 HZ and no phase or EQ dialed in on JL sub controls.

The way I choose to run, the Dali operates on it’s own and the subs do the same. At this low frequency the Class D amps in the subs don’t seem to effect the sound of the Megaline woofers, provided you filter the Class D amps at AC level and preamp level.

I had a buffer built so my preamp could not “see” the Class D subs and used Purist AC cables with network boxes.

The caps in the bottom of the Dali are part of the crossover and are supposed to protect against someone hooking up the crossover or amps in reverse. In other words, when someone puts woofer signal into ribbons the hope is to block signal before damage. These caps are always in the circuit and part of crossover frequency.

You ask about comparing Apogee versus Dali ribbons. These are two completely different designs. If you put big power into the Megaline, even with stock crossover and room light is shining on ribbon surface, you can frequently see the ribbon shimmer side to side, partially out of control.

I think it’s a miracle Dali designed such long ribbons and keep them operating perfectly but I would not want to exceed factory specs on range they operate in, any more than I would consider passing red line on a car engine repeatedly.

I have no comment on stuffing cabinet, I never tried that. The cabinet does seem a bit lightweight when you knuckle tap on it but I loved the sound so much I left it as is.  Think hollow body guitar versus solid body :-).  I believe Dali took this into consideration in the overall design. 

I had plans for even more mods and upgrades on the Megaline before I changed over to the Focal.  One included replacing built in spikes for Still Points.   Also wanted to change those caps we’ve been discussing, the ones in the base of the speaker.   Better quality could drastically reduce distortion on ribbons but suspect it would wind up needed a separate box  wired up outside the chassis to accommodate.

Also wanted to go further on the Dali-Tutay crossover, I was at third generation and was still coming up with design changes that were significant to sound.  The last thing I did was drastic, 1% copper foil Teflon caps for Tutay crossover.  The caps were a fortune to get built but was amazing upgrade.

cerrot- I checked out the website(in UK) & looks very professional with proof in the graphs. I’m curious what difference & how much of a difference you heard of the stock unit? I just may want it for the right price! ; -)

Mr Porter- I agree the Focal Grand Utopia EM is an awesome speaker(although I’ve never heard it but want to) & superior in many ways as you mentioned given the major price difference. I could only imagine what killer 16HZ linear bass they have with the 16” EM Focal woofers! (BTW- I love the stealth piano black look & wish the ML’s came in that finish) But, a point source speaker is a point source speaker no matter what the costs or material or design.  To me, nothing compares to a line source dipolar ribbon.

I didn’t mention that my subs are a pair of the new JL Gotham V2’s(I owned F212’s in the past) so I have no need for the ML’s to go lower 35HZ.. So combining them at 60HZ at 24DB with the ML’s 24 6” woofers running fullrange down to 35HZ is giving me more ‘sledgehammer slam’ factor than I ever heard or imagined being it at loud or low volume. In fact, try any track(especially at the beginning of #11 ‘Sifting’)  from Nirvana’s Bleach & listen at the kick drum. In the past 30 years with any speaker I have owned with this track there would be a loudness level  were distortion would set being it from the amps or driver(s) hitting there limit. Not so with the ML’s 24 6” woofers! In fact when it was slamming hard I checked the woofers & they were barely moving! The combo with the low distortion big JL Gotham woofers & low distortion mid/high bass ML woofers is just freakin’ incredible! BTW- My room is 17’Wx26’Lx8’H.

Regarding driving the ribbons beyond there limit is something I want & will avoid as I had to replace one of my first pair of Apogee Stage ribbon’s(back in 89’) after burning it up in the past when it arced to the protective mesh due to over driving it. When I went to audition the speaker at the previous owner’s house the ribbons were flapping loosely on a simple vocal tune with the stock crossover. I thought they were loose & I would have to adjust them when I got home. But when I hooked the up to the Beringer at 800HZ at 48DB the ribbons have not moved at all even when cranked up! So if they don’t move at all I should be fine should I not?!  

Also when I auditioned them with a close friend who is an audio engineer(former Threshold & Coda designer)  is much smarter than me & is a bigger audio nut than me noticed a hollow sound to then right off the bat. He knew right away what it was which is no damping material in the cabinet what so ever. Since the stock crossover is set at 1200HZ with a shallow slope we were hearing it echoing in the cabinet. So stuffing the cabinet & crossing it over lower with a much steeper slope cured that bigtime as my engineer bud recommended & knew. Yes, I’m sure stuffing the cabinet will affect the low bass slightly but that is not an issue with the Gotham’s!

I too want to replace the spikes in the future & Stillpoints would be perfect. I will have to go into more detail on how you planned on doing that & along with the cap replacement you mentioned. I was wondering also Mr. Porter if you were unsung the provided template as a listing guide?

Still up in the air on what perfect crossover I will be using in the future………

Ptheo, the modded unit was quieter than the unmodded.  They disconnect outputs 1 & 2 which keeps things further from the part of the unit where noise can come from.  It was black as night and totally transparent.  I would probably let it go for $550 + shipping.  Still have the box.  Not a scratch on it.